Objective Deep neck infection (DNI) associated with descending necrotizing mediastinitis (DNM) is a highly lethal condition. This retrospective review was performed to share our experience performing multidisciplinary management of DNI associated with DNM during a 7-year period. Methods We reviewed 16 patients who had been surgically treated for DNM at Peking Union Medical College Hospital from April 2010 to July 2017. The clinical outcomes were analysed to determine the most appropriate therapeutic strategy. Results Five women and 11 men were included in this study. Their mean age was 54.9 ± 14.3 years. DNM-associated infections most commonly occurred secondary to odontogenic infections (n = 10). Thirteen patients required tracheotomy because of tracheal compression. All patients underwent unilateral or bilateral cervicotomy. Six patients with DNM localized in the upper mediastinal space underwent transcervical mediastinal drainage, while 10 patients with DNM extending to the lower mediastinum were treated by cervicotomy and video-assisted thoracoscopic surgery. Three patients died of multiple organ failure. Conclusion Multidisciplinary treatment can achieve favourable outcomes in >80% of patients with DNM. Early diagnosis, proper airway management, and adequate surgical drainage are crucial for reducing mortality in patients with DNM, and minimally invasive procedures also play an important role.

Oral squamous cell carcinoma (OSCC) is a highly invasive lesion that frequently metastasizes to the cervical lymph nodes and is associated with a poor prognosis. Several adhesion factors, including cadherin 6 (CDH6), cadherin 11 (CDH11) and cluster of differentiation 44 (CD44), have been reported to be involved in the invasion and metastasis of multiple types of cancer. Therefore, the aim of the present study was to determine the expression of CDH6, CDH11 and CD44 in tumor tissues from patients with OSCC, and whether this was associated with the metastasis and survival of OSCC. The mRNA expression of the human tumor metastasis-related cytokines was examined by reverse transcription-quantitative polymerase chain reaction (RT-qPCR) in OSCC tumors with or without lymph node metastasis (n=10/group). The expression of CDH6, CDH11 and CD44 in 101 OSCC and 10 normal oral mucosa samples was examined by immunohistochemical staining. The association between overall and disease-specific survival times of patients with OSCC and the expression of these three proteins was evaluated using Kaplan-Meier curves and the log-rank test. RT-qPCR results indicated that the mRNA expression of CDH6, CDH11 and CD44 was increased in OSCC patients with lymph node metastasis (2.93-, 2.01- and 1.92-fold; P<0.05). Overexpression of CDH6, CDH11 and CD44 was observed in 31/35 (89%), 25/35 (71%) and 31/35 (89%) patients, respectively. The number of OSCC patients with lymph node metastasis exhibiting CDH6, CDH11 and CD44 overexpression was significantly higher than the number of patients without lymph node metastasis exhibiting overexpression of these proteins (P=0.017, P=0.038 and P=0.007, respectively). OSCC patients with high co-expression of CDH6, CDH11 and CD44 exhibited lower disease-specific survival times (P=0.047; χ=3.933) when compared with OSCC patients with low co-expression of these adhesion factors. CDH6, CDH11 and CD44 serve important roles in OSCC metastasis and the combined use of these factors as biomarkers may improve the accuracy of the prediction of cancer metastases and prognosis.

197 preoperative preparation, surgical implement and postoperative evaluation. All the clinical data were collected. Results: In the past five years, 3D printing technique was used in 27 clinical cases which microvascular free flap was used to reconstruct oral and maxillofacial defect. In our study, rapid prototyping 3D printing models were used to simulate the tumour ablation and evaluate the defect extension in 14 cases. In another 10 cases, 3D printed surgical templates were printed according to the preoperative digital design. For the third part, patient-specific maxillofacial implant were printed using 3D printing technique in three cases. All of the free flaps were survived and the final reconstructed results were satisfied in all patients. Conclusion: 3D printing technique had promising implication in oral and maxillofacial reconstruction. Preoperative rapid prototyping 3D printing model could be used to predict the extension of defects, simulate the reconstruction operation and prefabricated titanium mesh or plate. 3D printed surgical template was helpful for the accurate implementation of surgical plan.3D printing patient-specific implants were very useful to reconstruct complex 3 dimensional defects and obtain the best reconstructive result.